In the semiconductor industry, conductive interconnects have traditionally been formed using aluminum. However, conductive interconnects having a resistance lower than that given by aluminum are now required to meet the speed requirements of advanced semiconductor devices. Copper has recently been proposed as a replacement for traditional aluminum interconnects because of its lower resistance. Copper unlike aluminum, is highly mobile in many of the materials that are currently used to fabricate semiconductor devices. Thus, the use of copper interconnects in semiconductor devices requires the use of copper barrier layers to prevent unwanted copper diffusion within the semiconductor device. Adhesion of the barrier layer to the copper interconnect, however, is problematic and frequently causes semiconductor devices to fail. Therefore, a need exists for a metallization process that allows semiconductor devices with improved reliably to be fabricated with copper interconnects.